In which of the following states high yielding varieties of food grains were introduced as part of the first phase of Green Revolution (1966-72) ? 1. Andhra Pradesh 2. Tamil Nadu 3. Punjab 4. Haryana Select the correct answer using the code given below:

The first phase of the Green Revolution in India took place between 1966 and 1972. During this period, the government introduced High Yielding Variety (HYV) seeds, primarily for wheat, to combat food scarcity.

Because these seeds required intensive inputs like assured irrigation, chemical fertilizers, and pesticides, their introduction was restricted to regions with well-developed agricultural infrastructure. As a result, the first phase was highly concentrated in the northwestern states of Punjab, Haryana, and Western Uttar Pradesh.

While states like Andhra Pradesh and Tamil Nadu adopted HYV seeds (especially for rice) during the later phases of the Green Revolution, they were not the primary focus of the initial 1966-72 rollout. Therefore, only Punjab and Haryana from the given options were part of the first phase.